injured pigeon

I found a pigeon with a broken wing four/five weeks ago. Since it
coudn't fly at all and I didnt want it to end up being eaten up by a
cat, i took it in and have been feeding it since then. Now its wing
seems to have healed and it has no trouble flying(inside the house).
The only problem is that its wing droops down and it keeps it slightly
away from its body. I was wondering whether it would have any problem
flying long distances and whether I should just release it or take it
to a vet(there is a charity bird hosipital that i have just heard of).
I know I should have taken it earlier but I was busy and there arent
any vets nearby.

Also is there any way I could get it to keep coming back... say for
food/water ??